<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container{
            width: 920px;
            height: 380px;
           background: url(./images/背景图.jpg) no-repeat;
           margin: 40px auto;
        }
        .box{
            width: 720px;
            height: 300px;
            background: #ccc;
            position: absolute;
            top: 70px;
            left: 190px;
        }
        form{
            width: 300px;
            height: 200px;
            background: #fff;
            position: absolute;
            top: 40px;
            left: 200px;
        }
        form .form-group{
            display: inline-block;
            line-height: 30px;
            margin-top: 20px;
            margin-left: 40px;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="box">
            <form action="#">
                <div class="form-group">
                    <label for="username">账号</label>
                    <input type="text" placeholder="请输入账号">
                </div>
                <div class="form-group">
                    <label for="password">密码</label>
                    <input type="text" placeholder="请输入密码">
                </div>
                <div class="form-group">
                    <button>OK</button>
                </div>
            </form>
        </div>
    </div>
</body>
</html>